Definition: Operational snapshot

The snapshot at tick $s$ in $I$ is

Its classical labels include the identities and placements of live names, record values, and all retained controller data.

If $p_{\lambda }=\mathrm{Tr}{\omega }_{I,\lambda }>0$, its normalized conditional quantum state is ${\rho }_{I\mid \lambda }={\omega }_{I,\lambda }/p_{\lambda }$. At $p_{\lambda }=0$, no conditional state is assigned.